In a rare step, the FBI on Friday published scores of pages about confidential interviews with Hillary Clinton and others from its recently closed investigation into the former secretary of state's use of a private email server.

The FBI's investigation concluded Clinton never sought or asked permission to use a private server or email address during her tenure as the nation's top diplomat, which violated federal records keeping policies.

Clinton has repeatedly said her use of private email was allowed. But in July she told FBI investigators she "did not explicitly request permission to use a private server or email address," the FBI wrote. They said no one at the State Department raised concerns during her tenure, and that Clinton said everyone with whom she exchanged emails knew she was using a private email address.

The documents also include technical details about how the server in the basement of Clinton's home in Chappaqua, New York, was set up. Large portions of the documents were redacted.

Friday's release of documents involving the Democratic presidential nominee is a highly unusual step, but one that reflects extraordinary public interest in the investigation into Clinton's server.

After a yearlong investigation, the FBI recommended against prosecution in July, and the Justice Department then closed the case.

FBI Director James Comey said that while Clinton and her aides had been "extremely careless," there was no evidence they intentionally mishandled classified information.

The FBI director said the government found no direct evidence that Clinton's private server was hacked but said foreign government hackers were so sophisticated - and the server would be such a high-value target - that it was unlikely they would leave evidence of a break-in. Clinton told the FBI she was unaware of specific details about the security, software or hardware used on her server and occasionally received odd-looking emails. But she told agents there were never so many suspicious emails to cause concerns.

She also said she had no conversations about using a private email server to avoid her obligations under the Federal Records Act or the Freedom of Information Act.

Clinton told investigators that she directed her aides in early 2009 to create a private email account and that it was "a matter of convenience" for it to be moved onto a system maintained by her husband's staff.

She told investigators that "everyone at State knew she had a private email address because it was displayed to anyone with whom she exchanged emails," according to a summary of the July 1 interviewed released Friday by the FBI.

Clinton said that when top staff received an email, the recipient would evaluate whether the information should be forwarded to her, but no one "ever expressed a concern regarding the sensitivity of the content of these emails."